Work is directed toward clarifying local factors responsible for follicle rupture at the time of ovulation. Recent findings have led us to consider the basic requirements for ovulation at the level of the ovary. Emphasis is on: 1) determining whether a causal relationship exists between ovarian smooth muscle contractility and ovulation; 2) delineating the distribution of smooth muscle fibers in the human ovary by fluorescent antibody techniques; and 3) studying local ovarian requirements for ovulation, using an in vitro ovarian perfusion system. This newly developed model will be used for studies of nerve stimulation and for investigation of the effects of indomethacin, PGE2, PGF2 alpha, and alpha adrenergic agonists and blocking agents to determine whether inhibition of contractions alone can prevent ovulation. Ovulation in response to HMG-HCG will also be studied in the denervated monkey ovary. Fluorescent antibody techniques will also be used to localize prostaglandins in the ovary.